Co - Simulation capabilities from xMOD™
By Steve Streater, Flowmaster Product Manager, Mentor Graphics
It is almost universally recognized that simulation is a key factor in helping to reduce product development costs. In particular 1D models are an excellent basis for collaborative development, not only by the nature of their relatively small file sizes and fast run times, but by allowing virtual prototyping to be carried out much earlier in the design process before any CAD geometry is available.
As key enabler of collaborative development, co-simulation platform tools (also known as coupling environments or middleware), are finding growing popularity as a means of solving the ever more technically complex challenges that face automotive and aerospace system designers. However, co-simulation brings its own challenges and so we must recognize two fundamental co-simulation dichotomies. Firstly, coupling different simulation tools can be technically difficult, but conversely, large monolith models are unwieldy and computationally intensive.
Secondly, coupling via co-simulation platforms makes this task much easier, as it removes the need for the user to create a bespoke adapter, and provides a user-friendly environment for managing the co-simulation, but can mean significantly increased license costs. So these conflicting requirements inevitably mean that compromise is needed.
Against this industry backdrop, D2T’s xMOD™ product is the latest co-simulation platform tool to add a Flowmaster link to its compatibility list. This important development was the result of a collaboration with D2T under the Mentor Graphics OpenDoor Program, allowing a development license to be granted to D2T early in 2013, followed by market release of the Flowmaster® link for xMOD last October.
The over-arching concept for xMOD is that it is intended to link heterogeneous models through a versatile and efficient coupling process. This is achieved by optimising model execution through multi-cored and multi-threaded processing with individual solvers, and by providing a standalone model execution capability thus avoiding the need for separate application licenses. However, xMOD also provides some additional benefits, including compatibility with emerging standards through the integration of new simulation methodologies such as Functional Mock-up Interface (FMI), as well as continuity in the transition from Software-in-Loop (SiL) to Hardware-in-Loop (HiL). Finally, xMOD allows customization of graphical user interfaces which can be essential when facilitating ‘non-expert’ end user access.
xMOD is capable of running two principal simulation types. The first is Tool Coupling Co-simulation which is a conventional on-line simulation using separate processing for xMOD and each of the coupled applications. The second is Standalone Co-simulation which means an executable model is supplied to the xMOD simulation platform with the key difference being that the co-simulation is executed using a single computational process.
Not surprisingly, the Tool Coupling approach is higher cost, both in terms of CPU time and of course the application license requirements, but significantly it does provide the user with the flexibility to internally change the models. However, if the workflow is such that a Tier 1 supplier is providing models to its OEM customer, or indeed vice versa, this may not be an issue and indeed may be a distinct advantage! Furthermore the ability to select the ‘best tool for the job’, mean that this platform-based approach to vehicle development is increasingly finding favor with large OEMs, and complements Flowmaster’s product positioning. Consequently, the increasing popularity of the co-simulation platform, and its important role in facilitating supplier collaboration makes it an attractive alternative to the ‘one tool does everything’ methodology.
D2T’s compatibility table clearly illustrates the various tools that can now be linked to xMOD, and it can be seen that the new Flowmaster capability allows Tool Coupling Co-simulation, which was the stated priority of the lead customer. Going forward, D2T believe that extending the Flowmaster link to include Stand Alone Co-simulation is a feasible next step but like most enhancements will be driven by market demand…watch this space!
All images supplied by D2T